Potassium iodide in dermatology: a 19th century drug for the 21st century-uses, pharmacology, adverse effects, and contraindications

Clinical and forensic aspects of potassium iodide: Suddenly in high demand across Europe due to fears of radiation poisoning from a nuclear attack in Ukraine

Potassium iodide has demonstrated several therapeutic applications over time, being the choice for shielding the thyroid during radiation emergencies involving radioiodine release. Amidst the ongoing military conflict between Ukraine and Russia and the growing concern regarding the potential deployment of nuclear weapons, there has been a surge in the demand for potassium iodide across Europe. This work aimed to comprehensively review the current knowledge regarding the pharmacology, physiology, adverse effects, the protective role in reducing the risk of thyroid cancer and recommendations for potassium iodide use during radiation emergencies. Evidence on adverse effects is scarce, as potassium iodide is generally well-tolerated. Guidelines for thyroid blocking with potassium iodide during radiation emergencies suggest that, among populations vulnerable to radioiodine exposure, the benefits of potassium iodide outweigh the risks of adverse effects. Controversial topics surrounding the utilization of potassium iodide in radiation emergencies include the prophylaxis in iodine-deficient regions and following the detonation of dirty bombs, whether granule formulations versus tablets should be used and mental health concerns. Although the rise in demand seems to be a justified security measure, it is essential to recognize that potassium iodide protects the thyroid from radioiodine and does not impact the body's absorption of other radioactive materials or defend against external radiation exposure.

Treating Pythiosis with Antibacterial Drugs Targeting Protein Synthesis: An Overview

This review article explores the effectiveness of antibacterial drugs that inhibit protein synthesis in treating pythiosis, a difficult-to-treat infection caused by Pythium insidiosum. The article highlights the susceptibility of P. insidiosum to antibacterial drugs, such as macrolides, oxazolidinones, and tetracyclines. We examine various studies, including in vitro tests, experimental infection models, and clinical case reports. Based on our synthesis of these findings, we highlight the potential of these drugs in managing pythiosis, primarily when combined with surgical interventions. The review emphasizes the need for personalized treatment strategies and further research to establish standardized testing protocols and optimize therapeutic approaches.

Non-thionamide antithyroid drug options in Graves' hyperthyroidism

INTRODUCTION

The thionamide anti-thyroid drugs namely carbimazole, methimazole, and propylthiouracil, have been the predominant therapy modality for Graves' hyperthyroidism for over 60 years. Although these agents have proven efficacy and favorable side-effect profiles, non-thionamide alternatives are occasionally indicated in patients who are intolerant or unresponsive to thionamides alone. This review examines the available non-thionamide drug options for the control of Graves' hyperthyroidism and summarizes their clinical utility, efficacy, and limitations.

AREAS COVERED

We reviewed existing literature on mechanisms, therapeutic utility, and side-effect profiles of non-thionamide anti-thyroid drugs. Established non-thionamide agents act on various phases of the synthesis, release, and metabolism of thyroid hormones and comprise historical agents such as iodine compounds and potassium perchlorate as well as drug repurposing candidates like lithium, glucocorticoids, beta-blockers, and cholestyramine. Novel experimental agents in development target key players in Graves' disease pathogenesis including B-cell depletors (Rituximab), CD40 blockers (Iscalimab), TSH-receptor antagonists, blocking antibodies, and immune-modifying peptides.

EXPERT OPINION

Non-thionamide anti-thyroid drugs are useful alternatives in Graves' hyperthyroidism and more clinical trials are needed to establish their safety and long-term efficacy in hyperthyroidism control. Ultimately, the promise for a cure will lie in novel approaches that target the well-established immunopathogenesis of Graves' disease.

Selection of an Appropriate In Vitro Susceptibility Test for Assessing Anti-Pythium insidiosum Activity of Potassium Iodide, Triamcinolone Acetonide, Dimethyl Sulfoxide, and Ethanol

The orphan but highly virulent pathogen Pythium insidiosum causes pythiosis in humans and animals. Surgery is a primary treatment aiming to cure but trading off losing affected organs. Antimicrobial drugs show limited efficacy in treating pythiosis. Alternative drugs effective against the pathogen are needed. In-house drug susceptibility tests (i.e., broth dilution, disc diffusion, and radial growth assays) have been established, some of which adapted the standard protocols (i.e., CLSI M38-A2 and CLSI M51) designed for fungi. Hyphal plug, hyphal suspension, and zoospore are inocula commonly used in the drug susceptibility assessment for P. insidiosum. A side-by-side comparison demonstrated that each method had advantages and limitations. Minimum inhibitory and cidal concentrations of a drug varied depending on the selected method. Material availability, user experience, and organism and drug quantities determined which susceptibility assay should be used. We employed the hyphal plug and a combination of broth dilution and radial growth methods to screen and validate the anti-P. insidiosum activities of several previously reported chemicals, including potassium iodide, triamcinolone acetonide, dimethyl sulfoxide, and ethanol, in which data on their anti-P. insidiosum efficacy are limited. We tested each chemical against 29 genetically diverse isolates of P. insidiosum. These chemicals possessed direct antimicrobial effects on the growth of the pathogen in a dose- and time-dependent manner, suggesting their potential application in pythiosis treatment. Future attempts should focus on standardizing these drug susceptibility methods, such as determining susceptibility/resistant breakpoints, so healthcare workers can confidently interpret a result and select an effective drug against P. insidiosum.

Akute Schwellung im Halsbereich nach iodhaltigem Kontrastmittel – der oft unerkannte Iodmumps anhand von drei Fallbeispielen

Es werden drei Patientinnen vorgestellt, die zur Abklärung einer akuten Halsschwellung nach einer Untersuchung mit iodierten Kontrastmitteln zugewiesen wurden. Bei allen drei war ein akutes Angioödem vermutet worden, das allerdings nicht ausreichend auf Antihistaminika und Kortikosteroide ansprach. Es wurde schließlich ein sog. „Iodmumps“ oder Iod-assoziierte Sialoadenopathie diagnostiziert. Sonografisch und histologisch finden sich lediglich ein Ödem der Speicheldrüsen, hingegen keine Hinweise für eine ausgeprägte entzündliche Reaktion. Diese Komplikation ist nicht so selten und wird von Iod selbst ausgelöst, wie mit einer Provokation mit Iod-Kaliumiodid (Lugolʼscher Lösung) nachgewiesen werden konnte. Die pathophysiologisch ungeklärte Iod-assoziierte Sialoadenopathie wird somit als idiosynkratische Reaktion klassifiziert.

In Vitro Potentiation of Antimicrobial Photodynamic Inactivation by Addition of Potassium Iodide

The current increase in antibiotic resistance worldwide and the emergence of microbial strains that are resistant to all known antibiotics have stimulated research into novel strategies such as aPDI that are thought to be unlikely to lead to the development of resistance. Although many studies have reported in vitro aPDI killing of microorganisms by a range of different photosensitizers, there are still limitations to the effectiveness of aPDI, and recurrence of bacterial growth may occur in animal studies after completion of the illumination. In this chapter we cover a novel and relatively simple method to improve the efficacy of aPDI against Gram-positive Staphylococcus aureus, Gram-negative Escherichia coli, and fungal yeast Candida albicans by the addition of potassium iodide, a nontoxic inorganic salt. Under some circumstances up to six-logs additional killing can be obtained.

The Iodine Rush: Over- or Under-Iodination Risk in the Prophylactic Use of Iodine for Thyroid Blocking in the Event of a Nuclear Disaster

Iodine is an essential element for the production of thyroid hormones (THs). Both deficient and excess iodine intakes may precipitate in adverse thyroidal events. Radioactive iodine (RI) is a common byproduct of nuclear fission processes. During nuclear emergencies RI may be released in a plume, or cloud, contaminating the environment. If inhaled or ingested, it may lead to internal radiation exposure and the uptake of RI mainly by the thyroid gland that absorbs stable iodine (SI) and RI in the same way. A dose of radiation delivered to the thyroid gland is a main risk factor for the thyroid cancer development. The SI prophylaxis helps prevent childhood thyroid cancer. The thyroid gland saturation with prophylactic SI ingestion, reduces the internal exposure of the thyroid by blocking the uptake of RI and inhibiting iodide organification. However, negative impact of inadequate SI intake must be considered. We provide an overview on the recommended iodine intake and the impact of SI and RI on thyroid in children and adolescents, discussing the benefits and adverse effects of the prophylactic SI for thyroid blocking during a nuclear accident. The use of SI for protection against RI may be recommended in cases of radiological or nuclear emergencies, moreover the administration of iodine for prophylactic purposes should be cautious. Benefits and risks should also be considered according to age. Adverse effects from iodine administration cannot be excluded. Precise indications are mandatory to use the iodine for thyroid blocking. Due to this natural adaption mechanism it's possible to tolerate large doses of iodine without clinical effects, however, a prolonged assumption of the iodine when not needed can be dangerous and may precipitate in severe thyroidal and non-thyroidal negative effects.

Chromoblastomycosis in Latin America and the Caribbean: epidemiology over the past 50 years

Chromoblastomycosis is a chronic disease caused by melanized fungi that mainly affect individuals performing soil-related labour. The objective of this study was to analyse the epidemiological and clinical characteristics of chromoblastomycosis in Latin America and the Caribbean by an extensive literature review. An integrative review was performed of English, French, Portuguese, and Spanish publications in LILACS, SciELO, PubMed, SCOPUS and Web of Science databases covering the period 1969-2019. A total of 1,211 articles were identified, of which 132 were included in the review, covering 2,081 patients, 80.3% were male, the mean age was 56.1 years. The mean duration of the disease was 10.8 years. The lesions were mainly described in the lower limbs (60%). The most frequent clinical forms were verrucous (46.4%) and tumorous (21.7%). Major disease symptoms and signs consisted of itching and pain. Bacterial infection and functional limitation were important complications. Immunosuppression post-kidney transplantation was the most frequent comorbidity while leprosy was the main concomitant infectious disease. Fonsecaea pedrosoi and Cladophialophora carrionii were the predominant etiological agents. Majority of the cured cases were treated with itraconazole as monotherapy or in combination with other antifungals, surgery or cryosurgery. Chromoblastomycosis affects hundreds of rural workers in Latin America and the Caribbean, causing disability and personal, family and economic losses. It is important to prioritize epidemiological surveillance and early diagnosis of this disease in order to reveal its real prevalence and direct resources to preventive actions, diagnosis and early treatment.

LAY SUMMARY

Chromoblastomycosis is a slowly progressing chronic disease caused by melanized fungi. We collected data from South America and the Caribbean covering 1969-2019, the 132 articles included 2 081 patients, mean disease duration was 10.8 years. Fonsecaea pedrosoi and Cladophialophora carrionii predominated.

Rhinofacial conidiobolomycosis: Clinical and microbiological characterisation and shift in the management of a rare disease

BACKGROUND

Conidiobolomycosis is a rare tropical rhinofacial fungal infection which has not been well characterised. The available evidence in its management is sparse due to lack of clinical studies and the limited data on antifungal susceptibility patterns.

OBJECTIVE

To analyse the clinical manifestations, antifungal treatment and outcomes of patients with conidiobolomycosis and to determine antifungal susceptibility profiles of the isolates.

PATIENTS/METHODS

Retrospective analysis of data of all patients with a diagnosis of conidiobolomycosis confirmed by histopathology and culture at a tertiary care hospital from 2012 to 2019 was done.

RESULTS

There were 22 patients, 21 males and one female, with a mean age of 37.1 years. Most common presenting symptom was nasal obstruction, found in 20 (90.90%) patients. Patients who presented within 12 months had a better cure rate (85%) compared to those who presented late (67%). Among the 19 patients who had a follow-up, good outcome was seen in 15 of the 17 (88.24%) patients who were on itraconazole or potassium iodide containing regimen. Of the six patients who received additional trimethoprim-sulphamethoxazole (co-trimoxazole), 67% showed good outcome with two patients showing complete cure and two patients still on treatment with significant improvement. High minimum inhibitory concentration (MIC) values were noted for azoles and amphotericin B, whereas co-trimoxazole showed lowest MIC ranges.

CONCLUSION

Itraconazole and potassium iodide are reasonable first-line options for the treatment of conidiobolomycosis. Good clinical response to KI and comparatively lower MIC of co-trimoxazole are promising. Further studies are required for developing clinical breakpoints that can predict therapeutic outcomes.

Erythema Nodosum: A Practical Approach and Diagnostic Algorithm

Erythema nodosum is the most common form of panniculitis and is characterized by tender erythematous nodules mainly in the lower limbs on the pretibial area. The exact cause of erythema nodosum is unknown, although it appears to be a hypersensitivity response to a variety of antigenic stimuli. Although the etiology is mostly idiopathic, ruling out an underlying disease is imperative before diagnosing primary erythema nodosum. Erythema nodosum can be the first sign of a systemic disease that is triggered by a large group of processes, such as infections, inflammatory diseases, neoplasia, and/or drugs. The most common identifiable causes are streptococcal infections, primary tuberculosis, sarcoidosis, Behçet disease, inflammatory bowel disease, drugs, and pregnancy. We propose a diagnostic algorithm to optimize the initial work-up, hence initiating prompt and accurate management of the underlying disease. The algorithm includes an initial assessment of core symptoms, diagnostic work-up, differential diagnosis, and recommended therapies. Several treatment options for the erythema nodosum lesions have been previously reported; nevertheless, these options treat the symptoms, but not the triggering cause. Making an accurate diagnosis will allow the physician to treat the underlying cause and determine an optimal therapeutic strategy.

Feline sporotrichosis in Asia

Sporothrix schenckii sensu lato is currently recognized as a species complex with only Sporothrix brasiliensis, Sporothrix schenckii sensu stricto, Sporothrix globosa and Sporothrix pallida identified to cause disease in the cat. Feline sporotrichosis in Asia is mainly reported from Malaysia where a single clonal strain of clinical clade D, Sporothrix schenckii sensu stricto manifesting low susceptibility to major antifungal classes, has been identified as the agent of the disease. Sporothrix globosa has been identified to cause disease from a single cat in Japan while the specific species of agent has not been identified yet for the disease in Thailand. Despite efforts to elucidate and describe the pathogenicity of the agent and the disease it causes, the paucity of data highlights the need for further molecular epidemiological studies to characterize this fungus and the disease it causes in Asia. Its prognosis remains guarded to poor due to issues pertaining to cost, protracted treatment course, zoonotic potential and low susceptibility of some strains to antifungals.

The clinico-epidemiological characteristics and therapeutic experience of 152 patients with cutaneous sporotrichosis: a 10-year retrospective study from India

BACKGROUND

Cutaneous sporotrichosis, a subcutaneous mycosis because of Sporothrix schenckii, is sporadic worldwide with local hyperendemic pockets.

OBJECTIVES

To study clinico-epidemiological and therapeutic aspects of sporotrichosis in our clinic.

METHODS

We retrospectively analyzed medical records of 152 (M:F 52:100) patients with cutaneous sporotrichosis managed during 2010-2019.

RESULTS

All patients were involved in agricultural activities, and 63.2% were aged 21-60 years. Women outnumbered men by nearly two times. Fixed and lymphocutaneous sporotrichosis occurred in 54.6% and 43.4% patients, respectively. Only 2% of patients had multifocal sporotrichosis. Only 48% of patients imputed their disease to prior injuries. Extremities, upper in 53.9% and lower in 21% of patients, were mostly involved. Scrotum involvement in one patient was unusual. A mixed inflammatory infiltrate in 38.7%, chronic granuloma formation in 35%, and presence of spores in 48.9% biopsies was noted. S. schenckii grew on Sabouraud's dextrose agar in 40.2% of cases. Treatment with saturated solution of potassium iodide was curative in 76.8% patients, and lesions healed in 2-9 months (average 5.2 months). Metallic taste was experienced by 42.9% of patients. Itraconazole therapy was safe and effective in seven patients, and the response was better when combined with SSKI compared to either drug used alone.

CONCLUSION

Cutaneous sporotrichosis mostly affects persons during active years of life. The injuries predisposing to infection are mostly forgotten. Both fixed and lymphocutaneous sporotrichosis involving extremities remain common forms. SSKI alone or in combination with itraconazole is safe and effective treatment. Itraconazole is preferable in patients having preexisting hypothyroidism or intolerance to SSKI.

Top consumer uses of bestselling, single-ingredient vitamin and mineral supplements

OBJECTIVE

Vitamin and mineral supplements are widely used for self-care of a variety of medical conditions, but little is known about the specific conditions for which they are used. This study mined consumer product reviews to determine specific ways vitamin and mineral supplements are being used therapeutically.

DESIGN/SETTING

A cross-sectional analysis of user reviews for top-selling, single-ingredient vitamin and mineral products from a popular online retailer was performed to identify the most frequently appearing words associated with medical conditions. Results of individual analyses were compared to achieve consensus on the top, relevant keywords for each supplement. The full text of the reviews was searched for these keywords to distinguish whether they referred to therapeutic uses or adverse effects.

RESULTS

A total of 14 vitamin and 11 mineral supplements were analyzed. The number of user reviews for the analyzed products varied from 41 for manganese to over 5000 for biotin and vitamin D (median = 547 reviews per product). Cohen's kappa test for investigator-selected keywords related to medical conditions was generally greater than 0.6, indicating good interrater reliability. From these lists, the top consumer self-care uses were identified for 24 supplements. Commonly reported adverse effects were also noted for several products.

CONCLUSION

This study used data mining to identify the top ways consumers use an array of bestselling, single-ingredient vitamin and mineral supplements. These results can provide healthcare and nutrition professionals with information to anticipate the supplement-related education needs of patients and provide researchers with priority areas for clinical studies.

Disseminated Sporotrichosis: An Important Differential Diagnosis for Venous Ulcers

The authors present the case of a 45-year-old immunosuppressed man with lower extremity ulcers. Initially treated as venous ulcers, the wounds were later correctly diagnosed as cutaneous disseminated sporotrichosis. After appropriate treatment with systemic antifungals was initiated, the patient healed within 4 months.

Anti-Inflammatory Effects of Potassium Iodide on SDS-Induced Murine Skin Inflammation

Potassium iodide (KI), initially derived from seaweed in the early 19th century, is used for treating sporotrichosis in dermatological practice. KI has also been used to treat several noninfectious inflammatory skin diseases. However, the mechanisms underlying the improvement in such skin diseases remain unknown, and KI is not used widely. Thus, although KI is an old drug, physicians may not prescribe it frequently because they lack knowledge about it. Although KI is very inexpensive and causes few side effects, it has been superseded by new powerful and expensive drugs, such as biological agents. We applied 3% KI topically to areas of inflammation induced by SDS in mice. The levels of IL-1 and TNF-α gene expression were reduced, whereas that of IL-10 gene expression was increased. Small interfering RNA that was designed to reduce IL-10 gene expression levels was injected into the same mice, and the anti-inflammatory effects of KI were not observed. Thus, the pharmacologic action of KI is based on its anti-inflammatory effects caused by the increase in IL-10 levels. This information would increase dermatologists' awareness of KI as an efficacious and cost-effective treatment.

The threat of emerging and re-emerging pathogenic Sporothrix species

Sporotrichosis is a neglected subcutaneous mycosis of humans and animals acquired by traumatic inoculation of soil and plant material (classical route) contaminated with infectious propagules of the pathogen or being bitten/scratched by infected cats (alternative route). Within a genus composed of 53 species displaying an essentially environmental core, there are only a few members which have considerable impacts on human or animal health. Infections are typically caused by S. brasiliensis, S. schenckii or S. globosa. Rare mammal pathogens include members of the S. pallida and S. stenocereus complexes. To illustrate the tremendous impact of emerging zoonotic sporotrichosis on public health, we discuss the main features of the expanding epidemics driven by S. brasiliensis in cats and humans. The cat entry in the transmission chain of sporotrichosis, causing epizooties (cat-cat) or zoonosis (cat-human), has contributed to the definition of new paradigms in Sporothrix transmission, reaching epidemic levels, making the disease a serious public health problem. Indeed, S. brasiliensis infection in humans and animals is likely to become even more important in the future, with projections of its expansion in biogeographic domains and host range, as well as greater virulence in mammals. Therefore, lessons from a long-standing outbreak in the state of Rio de Janeiro about the source and distribution of the etiological agents among outbreak areas can be used to create better control and prevention plans and increase awareness of sporotrichosis as a serious emerging zoonotic disease.

Iodide Improves Outcome After Acute Myocardial Infarction in Rats and Pigs

OBJECTIVES

In this study, we tested whether iodide would reduce heart damage in rat and pig models of acute myocardial infarction as a risk analysis for a human trial.

DESIGN

Prospective blinded and randomized laboratory animal investigation.

SETTING

Animal research laboratories.

SUBJECTS

Sexually mature rats and pigs.

INTERVENTIONS

Acute myocardial infarction was induced by temporary ligation of the coronary artery followed by reperfusion. Iodide was administered orally in rats or IV in rats and pigs just prior to reperfusion.

MEASUREMENTS AND MAIN RESULTS

Damage was assessed by blood cardiac troponin and infarct size; heart function was determined by echocardiography. Blood peroxide scavenging activity was measured enzymatically, and blood thyroid hormone was determined using radioimmune assay. Iodide administration preserved heart function and reduced blood cardiac troponin and infarct size by approximately 45% in pigs and approximately 60% in rats. Iodide administration also increased blood peroxide scavenging activity and maintained thyroid hormone levels.

CONCLUSIONS

Iodide administration improved the structure and function of the heart after acute myocardial infarction in rats and pigs.

Iodide modulates protein damage induced by the inflammation-associated heme enzyme myeloperoxidase

Iodide ions (I^-) are an essential dietary mineral, and crucial for mental and physical development, fertility and thyroid function. I^- is also a high affinity substrate for the heme enzyme myeloperoxidase (MPO), which is involved in bacterial cell killing during the immune response, and also host tissue damage during inflammation. In the presence of H₂O₂ and Cl^-, MPO generates the powerful oxidant hypochlorous acid (HOCl), with excessive formation of this species linked to multiple inflammatory diseases. In this study, we have examined the hypothesis that elevated levels of I^- would decrease HOCl formation and thereby protein damage induced by a MPO/Cl^-/H₂O₂ system, by acting as a competitive substrate. The presence of increasing I^- concentrations (0.1-10 μM; i.e. within the range readily achievable by oral supplementation in humans), decreased damage to both model proteins and extracellular matrix components as assessed by gross structural changes (SDS-PAGE), antibody recognition of parent and modified protein epitopes (ELISA), and quantification of both parent amino acid loss (UPLC) and formation of the HOCl-biomarker 3-chlorotyrosine (LC-MS) (reduced by ca. 50% at 10 μM I^-). Elevated levels of I^- ( > 1 μM) also protected against functional changes as assessed by a decreased loss of adhesion (eg. 40% vs. < 22% with >1 μM I^-) of primary human coronary artery endothelial cells (HCAECs), to MPO-modified human plasma fibronectin. These data indicate that low micromolar concentrations of I^-, which can be readily achieved in humans and are readily tolerated, may afford protection against cell and tissue damage induced by MPO.

Can light-based approaches overcome antimicrobial resistance?

The relentless rise of antibiotic resistance is considered one of the most serious problems facing mankind. This mini-review will cover three cutting-edge approaches that use light-based techniques to kill antibiotic-resistant microbial species, and treat localized infections. First, we will discuss antimicrobial photodynamic inactivation using rationally designed photosensitizes combined with visible light, with the added possibility of strong potentiation by inorganic salts such as potassium iodide. Second, the use of blue and violet light alone that activates endogenous photoactive porphyrins within the microbial cells. Third, it is used for "safe UVC" at wavelengths between 200 nm and 230 nm that can kill microbial cells without damaging host mammalian cells. We have gained evidence that all these approaches can kill multidrug resistant bacteria in vitro, and they do not induce themselves any resistance, and moreover can treat animal models of localized infections caused by resistant species that can be monitored by noninvasive bioluminescence imaging. Light-based antimicrobial approaches are becoming a growing translational part of anti-infective treatments in the current age of resistance.

Morphological changes and phagocytic activity during the interaction of human neutrophils with Sporothrix schenckii: An in vitro model

Histopathological studies of human sporotrichosis lesions show pyogenic and granulomatous processes in which polymorphonuclear neutrophils (PMNs) play a central role. Few studies regarding the events associated with the interaction of human PMNs with Sporothrix schenckii have been made despite their importance in the clinical manifestations of the disease. In this study, human PMNs were co-cultured with conidia or yeast cells of S. schenckii to compare the phagocytic activity and morphological changes that could provide a clearer insight into the role of these phagocytes in the initial phase of sporotrichosis. PMNs showed increased cell size and separation of the nuclear lobes after phagocytosis. Through Scanning Electron Microscopy (SEM) analysis, an increase in cells with flattened filaments and vesicles on their surface was observed. Phagocytosed conidia showed a significant increase in width and size. The phagocytic activity was greater against yeasts than with conidia, but the viability of both S. schenckii cellular morphotypes was not drastically affected even after 2 h of co-culture. In conclusion, morphological changes in PMNs suggest that S. schenckii induces processes that may favor proinflammatory events. These phagocytes show a high ability to bind or ingest S. schenckii cells without affecting their viability. Morphological changes recorded in ingested conidia, suggest that this fungus could make the dimorphic switching in PMNs.

DO MULTIPLE ADMINISTRATIONS OF STABLE IODINE PROTECT POPULATION CHRONICALLY EXPOSED TO RADIOACTIVE IODINE: WHAT IS PRIODAC RESEARCH PROGRAM (2014-22) TEACHING US?

Single dose of potassium iodide (KI) is recommended to prevent the risk of thyroid cancer during nuclear accidents. However in the case of repeated/protracted radioiodine release, a unique dose of KI may not protect efficiently the thyroid against the risk of further developing a radiation-induced cancer. The new WHO guidelines for the use in planning for and responding to radiological and nuclear emergencies identify the need of more data on this subject as one of the four research priorities. The aims of the PRIODAC project are (1) to assess the associated side effects of repeated intakes of KI, (2) to better understand the molecular mechanisms regulating the metabolism of iodine, (3) to revise the regulatory French marketing authorization of 65-mg KI tablets and (4) to develop new recommendations related to the administration of KI toward a better international harmonization. A review of the literature and the preliminary data are presented here.

Potassium Iodide for Cutaneous Inflammatory Disorders: A Monocentric, Retrospective Study

OBJECTIVES

Potassium iodide (KI) is a medication that has been used for decades in dermatology and it is mentioned as a treatment option in all major dermatology textbooks. Yet, there is little recent information on its efficacy. In our study, we wanted to retrospectively evaluate the therapy response to KI in our patients.

METHODS

The hospital information system was searched for patients treated with KI at the Department of Dermatology (University Hospital Zurich) in the last 20 years (January 1, 1998 to December 31, 2017). A total of 52 patients were found and, subsequently, 35 patients were included in our study.

RESULTS

KI was prescribed for the following skin conditions: erythema nodosum, disseminated granuloma anulare, necrobiosis lipoidica, nodular vasculitis, cutaneous sarcoidosis, and granulomatous perioral dermatitis/ rosacea. The median duration of KI intake was 5 ± 7.7 weeks (range 1-26). The global assessment of efficacy by the treating physician showed an improvement of disease in about a third of all patients. No response was seen in 14 patients and 9 even had a progression of disease. An adverse event was documented in 16 cases.

CONCLUSIONS

Our findings show that an improvement was reached in only about a third of all cases. High response rates with only mild side effects (in 16 out of 35 patients) were observed.

Antimicrobial Photodynamic Inactivation Mediated by Tetracyclines in Vitro and in Vivo: Photochemical Mechanisms and Potentiation by Potassium Iodide

Tetracyclines (including demeclocycline, DMCT, or doxycycline, DOTC) represent a class of dual-action antibacterial compounds, which can act as antibiotics in the dark, and also as photosensitizers under illumination with blue or UVA light. It is known that tetracyclines are taken up inside bacterial cells where they bind to ribosomes. In the present study, we investigated the photochemical mechanism: Type 1 (hydroxyl radicals); Type 2 (singlet oxygen); or Type 3 (oxygen independent). Moreover, we asked whether addition of potassium iodide (KI) could potentiate the aPDI activity of tetracyclines. High concentrations of KI (200–400 mM) strongly potentiated (up to 5 logs of extra killing) light-mediated killing of Gram-negative Escherichia coli or Gram-positive MRSA (although the latter was somewhat less susceptible). KI potentiation was still apparent after a washing step showing that the iodide could penetrate the E. coli cells where the tetracycline had bound. When cells were added to the tetracycline + KI mixture after light, killing was observed in the case of E. coli showing formation of free molecular iodine. Addition of azide quenched the formation of iodine but not hydrogen peroxide. DMCT but not DOTC iodinated tyrosine. Both E. coli and MRSA could be killed by tetracyclines plus light in the absence of oxygen and this killing was not quenched by azide. A mouse model of a superficial wound infection caused by bioluminescent E. coli could be treated by topical application of DMCT and blue light and bacterial regrowth did not occur owing to the continued anti biotic activity of the tetracycline.

Human Pathogenic Entomophthorales

The pathogenic entomophthoralean fungi cause infection in insects and mammalian hosts. Basidiobolus and Conidiobolus species can be found in soil and insect, reptile, and amphibian droppings in tropical and subtropical areas. The life cycles of these fungi occur in these environments where infecting sticky conidia are developed. The infection is acquired by insect bite or contact with contaminated environments through open skin. Conidiobolus coronatus typically causes chronic rhinofacial disease in immunocompetent hosts, whereas some Conidiobolus species can be found in immunocompromised patients. Basidiobolus ranarum infection is restricted to subcutaneous tissues but may be involved in intestinal and disseminated infections. Its early diagnosis remains challenging due to clinical similarities to other intestinal diseases. Infected tissues characteristically display eosinophilic granulomas with the Splendore-Höeppli phenomenon. However, in immunocompromised patients, the above-mentioned inflammatory reaction is absent. Laboratory diagnosis includes wet mount, culture serological assays, and molecular methodologies. The management of entomophthoralean fungi relies on traditional antifungal therapies, such as potassium iodide (KI), amphotericin B, itraconazole, and ketoconazole, and surgery. These species are intrinsically resistant to some antifungals, prompting physicians to experiment with combinations of therapies. Research is needed to investigate the immunology of entomophthoralean fungi in infected hosts. The absence of an animal model and lack of funding severely limit research on these fungi.

Exploring the combination of SSKI and topical heparin in a case of erythema nodosum migrans

Erythema nodosum migrans (subacute nodular migratory panniculitis) is an uncommon type of panniculitis characterized by migrating subcutaneous nodules or plaque on the lower extremity. There are a very few cases of Erythema nodosum migrans reported and thus its appropriate treatment modality is not defined. We describe a case of a 30-year-old male with idiopathic erythema nodosum migrans which was manifest centrifugally spreading, slightly morpheaform erythematous plaque on the lower left leg. The patient was diagnosed initially and treated as a case of furunculosis with poor clinical response. The skin biopsy showed features consistent with subacute nodular panniculitis. Saturated Solution of Potassium Iodide along with topical Heparin successfully treated the patient, when the conventional treatment modalities failed. In a morpheaform centrifugally expanded plaque, erythema nodosum migrans should be kept in mind in the differential diagnosis, especially in the lower extremities in cases of unknown etiology.

Sporotrichosis: an update on epidemiology, etiopathogenesis, laboratory and clinical therapeutics

In the late 90's there was a change in both the route of transmission and the people at risk for sporotrichosis. This zoonotic cat-man alternative transmission route elicited changes in strategies to control the epidemic. There was a progressive increase in the number of cases involving especially children and the elderly. In addition to becoming hyperendemic, uncommon clinical pictures like immunoreactive clinical presentations or severe systemic cases have emerged. New species were identified and classified through molecular tools using more virulent clinical isolates, like S. brasiliensis, compared to the environmental isolates. Likewise, different species of Sporothrix have been associated with different geographic regions. The serological and molecular techniques are used as an auxiliary tool for the diagnosis and/or for species identification, although the isolation and the identification of Sporothrix spp. in clinical specimen is still the gold standard. Currently sporotrichosis epidemics requires the knowledge of the epidemiological-molecular profile to control the disease and the specific treatment. Itraconazole, potassium iodide, terfinafine, and amphotericin B are the available drugs in Brazil to treat sporotrichosis. The drug of choice, its posology, and treatment duration vary according to the clinical presentation, the Sporothrix species, and host immune status. New treatment choices, including a vaccine, are being developed; nevertheless, more clinical trials are required to confirm its efficacy.

Field-effect transition sensor for KI detection based on self-assembled calixtube monolayers

A series of novel calixarene-based tubes comprising different numbers of silatrane anchoring groups was synthesized. For the first time, a self-assembled monolayer (SAM) derived from calixtubes was formed on a SiO₂ surface. The formation of the SAM was confirmed by X-ray photoelectron spectroscopy, scanning electron microscopy-energy dispersive X-ray analysis, and contact angle measurements. Modification of the sensitive surface of a conventional ion-selective field effect transistor (ISFET) with the afforded SAM resulted in the production of a KI-sensitive sensor. This sensor selectively determined KI compare to different alkali metal iodides: NaI, RbI, CsI; also investigation of different potassium salts (acetate, iodide, nitrate, chloride, dihydrophosphate, perchlorate) showed the highest response to KI. This sensor was successfully employed to determine the presence of KI in artificial saliva with a limit of detection of ~3 × 10^-8 М. In addition, it was found that the detection limit of the sensor could be increased by combining the sensor with a microfluidic system. Due to the obtained sensor sensitivity and its ability to detect KI in artificial saliva, we could conclude that this sensor shows great potential for application in the determination of KI in different media, such as the human body and in biological liquids, such as saliva or urine.

A novel role of topical iodine in skin: Activation of the Nrf2 pathway

For a long time iodine has been used as an active dermal agent in the treatment of inflammatory, immune-mediated and infectious diseases. Moreover, topical iodine application has been reported to provide protection against sulfur-mustard-induced skin lesions, heat-induced and acid-induced skin burns in both haired guinea-pigs and mouse ear swelling models. However, the exact mechanism of action underlying these benefits of iodine has not yet been elucidated. In the current study, a novel mechanism of action by which iodine provides skin protection and relief, based on its electrophilic nature, is suggested. This study demonstrates that both iodine and iodide are capable of activating the Nrf2 pathway in human skin. As a result, skin protection against UVB-induced damage was acquired and the secretion of pro-inflammatory cytokines (IL-6, IL-8) from LPS-challenged skin was reduced. Iodide role in the enhanced activation of this pathway is demonstrated. The mode of action by which iodine and iodide activate the Nrf2 pathway is discussed.

Association of itraconazole and potassium iodide in the treatment of feline sporotrichosis: a prospective study

Feline sporotrichosis is an endemic disease in Rio de Janeiro, Brazil, where zoonotic transmission of Sporothrix spp. has been reported since 1998. Itraconazole (ITZ) remains the first choice for treating this disease in cats. However, there have been reports of therapeutic failure and a long-term endeavor. Potassium iodide (KI), considered in the past as a drug with variable effectiveness in cats with sporotrichosis, arises as an important option in the treatment of cats from the endemic area of Rio de Janeiro. In order to evaluate the effectiveness of the association of ITZ and KI in naive cats with sporotrichosis, a prospective cohort study was conducted on 30 cats receiving ITZ 100 mg/day and KI 2.5 mg-20 mg/kg/day. Clinical and laboratory adverse effects were assessed once a month according to the standard care protocol. The cure rate was 96.15% within a median of 14 weeks of treatment. Adverse effects were observed in 50% of cats and were managed with a temporary drug suspension and/or a hepatoprotective therapy. The association of ITZ and KI emerges as an effective option for the treatment of feline sporotrichosis.

Subcutaneous entomophthoromycosis mimicking soft-tissue sarcoma in children

AIM

Subcutaneous entomophthoromycosis (EM) is an uncommon fungal infection of childhood. This article is intended to draw the attention of pediatric surgeons to the fact that EM can mimic soft-tissue tumor.

METHODS

It is a retrospective review of 16 children treated for subcutaneous EM between 2000 and 2013.

RESULTS

The median age of patients was 3.5 years. The typical lesion was a discoid subcutaneous mass that can be easily lifted from deeper tissues (the doughnut lifting sign). Lesions were mostly distributed in the lower half of body. All the patients were immunocompetent. Correct clinical diagnosis was made only in 4 cases while others were mistaken for a tumor. All the 8 children who underwent wide excision of the pseudotumor had local recurrence. Supersaturated solution of potassium iodide was curative in 11 cases while addition of itraconazole was needed in one case. One child died of multi-drug resistant infection. The mean treatment duration was 4.7 months (range 2-8 months).

CONCLUSION

Subcutaneous EM can mimic soft-tissue tumor. High index of suspicion is essential to avoid misdiagnosis and inappropriate treatment. A newly described "doughnut-lifting sign' may be helpful in clinical diagnosis. Emergence of multi-drug resistant infection is a source of concern.

Bacterial photodynamic inactivation mediated by methylene blue and red light is enhanced by synergistic effect of potassium iodide

The inexorable increase of antibiotic resistance occurring in different bacterial species is increasing the interest in developing new antimicrobial treatments that will be equally effective against multidrug-resistant strains and will not themselves induce resistance. One of these alternatives may be photodynamic inactivation (PDI), which uses a combination of nontoxic dyes, called photosensitizers (PS), excited by harmless visible light to generate reactive oxygen species (ROS) by type 1 (radical) and type 2 (singlet oxygen) pathways. In this study, we asked whether it was possible to improve the efficacy of PDI in vitro and in vivo by addition of the inert salt potassium iodide (KI) to a commonly investigated PS, the phenothiazinium dye methylene blue (MB). By adding KI, we observed a consistent increase of red light-mediated bacterial killing of Gram-positive and Gram-negative species in vitro and in vivo. In vivo, we also observed less bacterial recurrence in wounds in the days posttreatment. The mechanism of action is probably due to formation of reactive iodine species that are produced quickly with a short lifetime. This finding may have a relevant clinical impact by reducing the risk of amputation and, in some cases, the risk of death, leading to improvement in the care of patients affected by localized infections.

One-pot green synthesis of reduced graphene oxide (RGO)/Fe3O4 nanocomposites and its catalytic activity toward methylene blue dye degradation

The reduced graphene oxide (RGO)/Fe3O4 nanocomposites were synthesized through a facile one-pot green synthesis by using solanum trilobatum extract as a reducing agent. Spherical shaped Fe3O4 nanoparticles with the diameter of 18 nm were uniformly anchored over the RGO matrix and the existence of fcc structured Fe3O4 nanoparticles over the RGO matrix was ensured from X-ray diffraction patterns. The amide functional groups exist in the solanum trilobatum extract is directly responsible for the reduction of Fe(3+) ions and GO. The thermal stability of GO was increased by the removal of hydrophilic functional groups via solanum trilobatum extract and was further promoted by the ceramic Fe3O4 nanoparticles. The ID/IG ratio of RGO/Fe3O4 was increased over GO, indicating the extended number of structural defects and disorders in the RGO/Fe3O4 composite. The catalytic efficiency of prepared nanostructures toward methylene blue (MB) dye degradation mediated through the electron transfer process of BH4(-) ions was studied in detail. The π-π stacking, hydrogen bonding and electrostatic interaction exerted between the RGO/Fe3O4 composite and methylene blue, increased the adsorption efficiency of dye molecules and the large surface area and extended number of active sites completely degraded the MB dye within 12 min.

Sporotrichosis: an overview and therapeutic options

Sporotrichosis is a chronic granulomatous mycotic infection caused by Sporothrix schenckii, a common saprophyte of soil, decaying wood, hay, and sphagnum moss, that is endemic in tropical/subtropical areas. The recent phylogenetic studies have delineated the geographic distribution of multiple distinct Sporothrix species causing sporotrichosis. It characteristically involves the skin and subcutaneous tissue following traumatic inoculation of the pathogen. After a variable incubation period, progressively enlarging papulo-nodule at the inoculation site develops that may ulcerate (fixed cutaneous sporotrichosis) or multiple nodules appear proximally along lymphatics (lymphocutaneous sporotrichosis). Osteoarticular sporotrichosis or primary pulmonary sporotrichosis are rare and occur from direct inoculation or inhalation of conidia, respectively. Disseminated cutaneous sporotrichosis or involvement of multiple visceral organs, particularly the central nervous system, occurs most commonly in persons with immunosuppression. Saturated solution of potassium iodide remains a first line treatment choice for uncomplicated cutaneous sporotrichosis in resource poor countries but itraconazole is currently used/recommended for the treatment of all forms of sporotrichosis. Terbinafine has been observed to be effective in the treatment of cutaneous sporotrichosis. Amphotericin B is used initially for the treatment of severe, systemic disease, during pregnancy and in immunosuppressed patients until recovery, then followed by itraconazole for the rest of the therapy.

Iodide protects heart tissue from reperfusion injury

Iodine is an elemental nutrient that is essential for mammals. Here we provide evidence for an acute therapeutic role for iodine in ischemia reperfusion injury. Infusion of the reduced form, iodide, but not the oxidized form iodate, reduces heart damage by as much as 75% when delivered intravenously following temporary loss of blood flow but prior to reperfusion of the heart in a mouse model of acute myocardial infarction. Normal thyroid function may be required because loss of thyroid activity abrogates the iodide benefit. Given the high degree of protection and the high degree of safety, iodide should be explored further as a therapy for reperfusion injury.

Use of potassium iodide in dermatology: updates on an old drug

Potassium iodide, as a saturated solution, is a valuable drug in the dermatologist's therapeutic arsenal and is useful for the treatment of different diseases due to its immunomodulatory features. However, its prescription has become increasingly less frequent in dermatology practice. Little knowledge about its exact mechanism of action, lack of interest from the pharmaceutical industry, the advent of new drugs, and the toxicity caused by the use of high doses of the drug are some possible explanations for that. Consequently, there are few scientific studies on the pharmacological aspects, dosage and efficacy of this drug. Also, there is no conventional standard on how to manipulate and prescribe the saturated solution of potassium iodide, which leads to unawareness of the exact amount of the salt being delivered in grams to patients. Considering that dosage is directly related to toxicity and the immunomodulatory features of this drug, it is essential to define the amount to be prescribed and to reduce it to a minimum effective dose in order to minimize the risks of intolerance and thus improve treatment adherence. This review is relevant due to the fact that the saturated solution of potassium iodide is often the only therapeutic choice available for the treatment of some infectious, inflammatory and immune-mediated dermatoses, no matter whether the reason is specific indication, failure of a previous therapy or cost-effectiveness.

A history of multiple sclerosis investigations in Canada between 1850 and 1950

The medical profession's modern quandaries with Multiple Sclerosis (MS) largely began in 1849, with Friedrich von Frerichs' (1819-1885) early description of the clinical and pathological features of what he termed Hirnsklerose ("brain sclerosis"). This manuscript is an overview of the century of research (1850-1950) that followed the emergence of this clinical entity, with a focus on the hitherto under-explored English Canadian perspective. Using journal articles, reviews, and case studies, this historiographical paper reviews what may be some of the earliest recorded cases of MS in Canada, and outlines the diagnostic challenges that confronted early Canadian physicians in their encounters with MS. Early Canadian attempts to characterize the aetiology and epidemiology of MS and treat it are also discussed. These activities were influenced by developments in the field in Europe and the United States, and helped set the stage for the modern era of immunologic and therapeutic research on MS.

Sporotrichosis: a forgotten disease in the drug research agenda

Potassium iodide was discovered in the 19th century and still remains as one of the more effective and most prescribed treatments for sporotrichosis. No new drugs have been evaluated in large randomized clinical trials in comparison with standard or alternative treatments for sporotrichosis during the last decades. The emergence of disseminated sporotrichosis in AIDS patients has uncovered the need for more effective treatments. Sporotrichosis is only a public health problem in a few geographical areas, mostly located in developing countries; and its usually harmless history could explain the limited investment in sporotrichosis treatment research. Better understanding of the virulence factors, such as the melanization process, could reveal new potential drug targets.

Subcutaneous phaeohyphomycosis of the face presenting as rhinoentomophthoramycosis

OBJECTIVES

Subcutaneous phaeohyphomycosis is the most common variety of phaeohyphomycosis and presents as asymptomatic or mildly painful, localized cysts, abscesses, or sometimes chromoblastomycosis-like lesions over the feet, legs, or hands in about 60-85% of cases. It usually afflicts adults with some degree of immunosuppression.

METHODS

We report a 30-year-old man, who presented with features of recurrent sinusitis (episodes of fever, nasal stuffiness, paranasal sinus pain, and tenderness), mucosal hypertrophy of the maxillary sinuses, and mid-face swelling that was freely mobile and suggestive of rhinoentomophthoramycosis. He had no other associated illness.

RESULTS

Histology suggested tumid lupus erythematosus. The diagnosis was based on Fonsecaea pedrosoi cultured from a biopsy specimen.

CONCLUSIONS

Combination therapy with itraconazole and saturated solution of potassium iodide (SSKI) was more effective than itraconazole used alone.

Adverse effects of iodine thyroid blocking: a systematic review

(131)I, when released in a radiological or nuclear accident as happened recently in Fukushima, Japan, may cause thyroid cancer as a long-term consequence. Iodine thyroid blocking (ITB) is known to reduce the risk of developing thyroid cancer. Potential adverse effects of ITB have not been systematically investigated so far. This article summarises the results of a review on adverse effects of ITB based on a systematic literature search in scientific medical databases. A meta-analysis was not performed as identified studies displayed major heterogeneity. The search resulted in 14 articles relevant to the topic, reporting mostly on surveys, ecological and intervention studies. Only one study from Poland focused on effects (both desired and adverse) of an ITB intervention following the Chernobyl accident. All other studies reported on iodine administration in a different context. Overall, the studies did not reveal severe adverse reactions to potassium iodide in the general public. Since ITB is a protective measure only applied in very specific circumstances, scientifically sound studies of adverse effects are scarce and consequently the evidence base is weak. The assessment of adverse effects of ITB relies on indirect evidence from related areas. This study may contribute to ongoing developments in pharmacoepidemiology aiming to better quantify adverse effects of medications and health care interventions including ITB.

Potassium iodide capsule treatment of feline sporotrichosis

Sporotrichosis is a mycosis caused by Sporothrix schenckii. The most affected animal is the cat; it has played an important role in the zoonotic transmission of this disease, especially in Rio de Janeiro, Brazil, since 1998. In order to evaluate the treatment of feline sporotrichosis with potassium iodide, an observational cohort was conducted in 48 cats with sporotrichosis at Instituto de Pesquisa Clínica Evandro Chagas, Fiocruz. All cats received potassium iodide capsules, 2.5 mg/kg to 20 mg/kg q24h. The cure rate was 47.9%, treatment failure was 37.5%, treatment abandonment was 10.4% and death was 4.2%. Clinical adverse effects were observed in 52.1% of the cases. Thirteen cats had a mild increase in hepatic transaminase levels during the treatment, six of them presented clinical signs suggestive of hepatotoxicity. Compared to previous studies with itraconazole and iodide in saturated solution, potassium iodide capsules are an alternative for feline sporotrichosis treatment.

Successful treatment of terbinafine in a case of sporotrichosis

Sporotrichosis is a chronic subacute infection caused by fungi belonging to the Sporothrix Complex. In the present clinical case, nasal sporotrichosis was treated with potassium iodide. This was unsuccessful, and the treatment was restarted with a combination of potassium iodide and itraconazole. This however resulted in a further recurrence of the infection. The mycological cultures were tested in vitro for antifungal activity to assist in treatment. Terbinafine, an antifungal drug, produced the best results and was therefore used for the rest of the treatment course, with no recurrence after two years of its completion. In addition, both cultures were compared using RAPD and different fragment patterns were observed. This indicated that the isolates were either different or indicated a microevolutionary process of this microorganism.